1. The document discusses molecular physics, specifically the first law of thermodynamics regarding energy changes in processes. It defines internal energy (U) as the sum of kinetic energy from motion and potential energy from interactions between particles in a system.
2. It explains how internal energy depends on the state of the system and can change through work or heat transfer. The first law of thermodynamics states that energy change in a system equals the heat transferred plus the work done.
3. It also discusses how internal energy can change through work done by or on the system, and how this relates to pressure-volume work based on the gas laws.
1. The document discusses molecular physics, specifically the first law of thermodynamics regarding energy changes in processes. It defines internal energy (U) as the sum of kinetic energy from motion and potential energy from interactions between particles in a system.
2. It explains how internal energy depends on the state of the system and can change through work or heat transfer. The first law of thermodynamics states that energy change in a system equals the heat transferred plus the work done.
3. It also discusses how internal energy can change through work done by or on the system, and how this relates to pressure-volume work based on the gas laws.